Fluid Application

In fluid application, the metal removal fluid is delivered to the machine tool so the MRF can cool and lubricate the metal during the machining or grinding process. During application, mist can be generated, or MRF can splash. Since the goal is to keep the fluid clean and to keep workers from unnecessary exposure, certain considerations must be taken into account when an MRF delivery system is designed.

What are the design considerations for metal removal fluid delivery systems?

There are two major considerations in the design of MRF delivery systems:

Workers should not be needlessly exposed to the fluid.

The fluid should not become contaminated nor otherwise altered

Metal removal fluid delivery systems should be designed to generate a minimum amount of metal removal fluid aerosols (mist). Fluid flows should be directed to prevent splashing. For transfer line machines, as the earliest operation in the line often involves the heaviest metal removal cut, early operations may contribute most to metal removal fluid aerosol generation.

How can exposure of employees to mist and vapors be reduced?

There are 3 basic steps that can be taken to reduce employee exposure to mist and vapors:

Maintain components.

Leaking seal packing, leaking mechanical seals, and leaking ports in delivery pumps allow air into the metal removal fluid, which increases the amount of mist produced.

Use the minimum adequate fluid pressure.

A generous, low-pressure flow of MRF delivered directly to the cutting zone, where it floods and cools the workpiece and cutting tool, is usually most effective. A high-pressure delivery of MRF may create mists, may not supply adequate cooling or lubrication, and may not have sufficient flow to properly remove swarf or chips from the cutting area.

Interrupt or reduce the flow of MRF when practical.

The flow of MRF should be interrupted when machining is not occurring. This not only reduces mechanically generated mist, it also reduces degradation of the MRF and oxidation of the biocides. An intermittent flow (or change in pressure) of the MRF (e.g., 30 seconds on, then 2 minutes off) may often be more effective at moving chips than a continuous flow.